Chuck Yeager is not related to Jeana Yeager, one of the two pilots of the Rutan Voyager aircraft, which circled the world without landing or refueling. The name "Yeager" (disebut /ˈjeɪɡər/) is an Anglicized form of the German, Dutch and Scandinavian name, Jäger (German: "hunter") , and so is common among immigrants of those communities. He is the uncle of former baseball catcher Steve Yeager.

Yeager enlisted as a private in the U.S. Army Air Forces (USAAF) pada 12 September 1941, and became an jurumekanik kapal terbang at George Air Force Base, Victorville, California. At enlistment, Yeager was not eligible for flight training because of his age and educational background, but the entry of the U.S. into World War II less than two months later prompted the USAAF to alter its recruiting standards. Blessed with remarkable 20/10 vision, Yeager displayed natural talent as a pilot and was accepted for flight training. He received his wings and a promotion to Flight Officer at Luke Field, Arizona, where he graduated from class 43C on March 10, 1943. Assigned to the 357th Fighter Group at Tonopah, Nevada, he initially trained as a fighter pilot flying P-39 Airacobras (earning a seven day grounding order for pruning a tree belonging to a local farmer during a training flight),[3] and went overseas with the group on November 23, 1943.

P-51D-20NA Glamorous Glen III, is the aircraft in which Chuck Yeager pilot achieved most of his aerial victories.

Stationed in the United Kingdom at RAF Leiston, Yeager flew P-51 Mustangs in combat (he named his aircraft Glamorous Glennis[4] after his girlfriend, Glennis Faye Dickhouse, who became his wife in February 1945) with the 363rd Fighter Squadron. He had gained one victory before he was shot down over France on his eighth mission, on March 5, 1944.[5] He escaped to Spain on March 30 with the help of the Maquis (French Resistance) and returned to England on May 15, 1944. During his stay with the Maquis, Yeager assisted the guerrillas in duties that did not involve direct combat, though he did help to construct bombs for the group, a skill that he had learned from his father.[6] He was awarded the Bronze Star for helping another airman, who had lost part of his leg during the escape attempt, to cross the Pyrenees.

Despite a regulation that "evaders" (escaped pilots) could not fly over enemy territory again to avoid compromising Resistance allies, Yeager was reinstated to flying combat. Yeager had joined a bomber pilot evader, Capt. Fred Glover, in speaking directly to the Allied Supreme Commander, General Dwight D. Eisenhower, on June 12, 1944. With Glover pleading their case, arguing that because the Allies had invaded France, the Maquis resistance movement was by then openly fighting the Nazis alongside Allied troops, so there was little or nothing they could reveal if shot down again to expose those who had helped them evade capture. Eisenhower, after gaining permission from the War Department to decide the requests, concurred with Yeager and Glover. Yeager later credited his postwar success in the Air Force to this decision, saying that his test pilot career followed naturally from being a decorated combat ace with a good kill record, along with being an airplane maintenance man prior to attending pilot school. In part because of his maintenance background, Yeager also frequently served as a maintenance officer in his flying units.

Yeager possessed outstanding eyesight (rated as 20/10, once enabling him to shoot a deer at 600 ela (550 m)[7]), flying skills, and combat leadership; he distinguished himself by becoming the first pilot in his group to make "ace in a day": he shot down five enemy aircraft in one mission, finishing the war with 11.5 official victories, including one of the first air-to-air victories over a jet fighter (a German Messerschmitt Me 262). Two of his "ace in a day" kills were scored without firing a single shot; he flew into firing position against a Messerschmitt Bf 109 and the pilot of the aircraft panicked, breaking to starboard and colliding with his wingman; Yeager later reported both pilots bailed out. Another victory that was not officially counted for him came during the period before his combat status was reinstated: during a training flight in his P-51 over the North Sea, he happened on a German Junkers Ju 88 heavy fighter attacking a downed B-17 Flying Fortress crew. Yeager's quick thinking and reflexes saved the B-17 crew, but because he was not yet cleared for flying combat again, his gun camera film and credit for the kill were given to his wingman, Eddie Simpson. (Yeager later mistakenly recalled that the credit had given Simpson his fifth kill).

In his 1986 memoirs, he noted with disgust that "atrocities were committed by both sides" and went on to recount going on a mission with orders from the Eighth Air Force to "strafe anything that moved".[8][9] During the mission briefing he whispered to Major Donald H. Boschkay; "if we are going to do things like this, we sure as hell better make sure we are on the winning side".[8][9] He further noted "I’m certainly not proud of that particular strafing mission against civilians. But it is there, on the record and in my memory."[10][11]

Yeager was commissioned a second lieutenant while at Leiston and was promoted to captain before the end of his tour. He flew his sixty-first and final mission on January 15, 1945, and returned to the United States in early February. As an evader, he received his choice of assignments and, because his new wife was pregnant, chose Wright Field to be near his home in West Virginia. His high flight hours and maintenance experience qualified him to become a functional test pilot of repaired aircraft, which brought him under the command of Colonel Albert Boyd, head of the Aeronautical Systems Flight Test Division.[12]